Schema files with local and external schema references #6855
Description
Describe the bug
With #6815 there are schema files introduced and used on importing data and internal meta data file access. But some of them use references to local schema files and some of them are using references to external URL schema files.
F.e. ead.xsd, mods.xsd and xslt20.xsd are using references to other xsd over an URI path which results that on validating with this schema's the additional external schema files get downloaded. This may be non issue if you only validate a few times but if you do f.e. an mass import than there will be a load of validations and accesses to this external schema files.
Expected behavior
The external referenced schema files should be added to the repository and the reference should be changed to this local files.
Additional context
mods.xsd and xslt20.xsd are referencing to similar named xsd file xml.xsd but they have different URI's and are not similar and should be stored and references in different file names.